Power of 300TDi

On Mon, 01 Nov 2004 07:19:02 +0000, Austin Shackles
>you could perhaps do it with a morse chain a la V8, but I suspect that gets
>away with no tensioner by being very short.
>
>the gear set is cute, no doubt. How do they get lubricated? or don't they?

The gears are lubricated with engine oil. The kit includes a new inner
timing case and this picks up the oil via a banjo plug from the oil
gallery below the camshaft.

You can see the result at this link

http://www.yican.com.au/Diary/50km.html


The oil galleries within the case spray feed out of the two idler
gears (between pump and camshaft gears, and camshaft gear and
crankshaft gear).

The oil then gravity feeds back into the sump via a drain hole in the
bottom of the timing case.

I will be publishing some more photos in about a month as the gears
will have then covered their first 100000kms.


Cheers


Phillip Simpson

On Monday, in article <[email protected]>
[email protected] "EMB" wrote:

> Steve Taylor wrote:
> > EMB wrote:
> >
> >> Given how critical diesel injector pump timing is I think a chain
> >> would tend to be unsatisfactory in the accuracy stakes.
> >
> >
> > Why ? Its the way it was done for years, before manufacturers reckoned
> > on making quieter and cheaper timing gear. The tolerances created by the
> > backlash in a gear train are not negligible.
>
> Factory fit chains tend to have a hydraulic tensioner, AFAICT there's no
> easy way to retrofit one to the front of a Tdi.
>
> As for gear tolerances, my Chev racecar engines fitted with timing gears
> have no discernable timing movement (ie <1/4 degree) as opposed to the
> (high quality) chain driven ones that have up to 1 degree of "movement"
> in the timing setting.

It's going to be when you take your foot off the throttle that any
backlash in the drive system shows, and I doubt the pump would be trying
very hard to maintain a speed. It has to do work to deliver the fuel.

Now, chain wear is going to increase the effective pitch on a tensioned
run, and affect the relationship between the input and output of the
drive. Eventually, in systems carrying a heavy load, the effect will
concentrate the forces on one sprocket tooth at a time. From what I've
seen, chain driven timing gear is grossly over-specified in terms of
chain and sprocket contact surfaces, so that sort of wear will be
minimised. Besides, they're in a much friendlier environment than the
chains on the average combine harvester.

--
David G. Bell -- SF Fan, Filker, and Punslinger.

"History shows that the Singularity started when Sir Tim Berners-Lee
was bitten by a radioactive spider."

> Hi Peter,
> have to agree that they can snap, but also disagree about them
> stretching. In fact if you fit a belt part of the installation process
> is to tighten them tightly, turn the engine around a couple of times,
> and then retighten them. Even with this process they stretch in a very
> short time.

the amount of stretch is almost imperceptable on modern timing belts.
When i compared my old belt against the new belt for wear when i
changed it last, i could not tell any difference due to stretching.
Can`t say i was looking too hard though. Looking at the length of the
belt fitted to a 300tdi and assuming a 2 degree error would be
noticeable in the timing, the belt would need to stretch 5mm in
length!!! Mine certainly hadn`t after being used and definitely abused
for 60,000 miles!
>
>
> Speaking to owners I had one customer who noticed that over a period
> of some 9 months his vehicle was slowing loosing power. (he and a
> fishing mate, used to both drive up a long steepish hill in their
> vehicles. Initially the 300Tdi always beat the Pajero(Shogun?) but
> this changed to a draw, then the pajero would always win the race up
> the hill.)

You`ll probably find that was more to do with fuel and air filters and
lack/need of a service than the timing belt. Defenders are very prone
to clogging up air filters with dust and it makes a huge difference to
the performance. I didn`t notice ANY difference in power before and
after the belt was done. None at all. And i use low rev power ALOT as
its constantly used offroad and for dragging caravans around. However
about 3000 miles after a service it gets very sluggish and i usually
end up doing a mini service to replace the air filter. normal power is
then returned.
>

> Even with a new belt I've never seen a 300Tdi pull properly down to
> 1100rpm like I can do anytime I need to (mud,snow,sand driving etc).I
> also like the extra economy you get from the 300Tdi with the gears,
> especially since the price of fuel is increasing.
>
>
You`ve never driven mine then! My defender 300tdi is completely
standard (engine wise) and pulls like a trojan horse from tickover. A
properly set up tdi is a brilliant engine. More likely factors in
performance would be injectors, air and fuel filter, correctly set up
injection pump, lift pump working properly (amazing how many tdis
suffer poor performance from weak lift pumps not supplying enough
motion lotion!) and carbon build up in the head.

I may be swayed if you were able to give independant comparisons of
rolling road / dyno tests of brand new engines before and after the
conversion.


> Cheers
>
Nick

"Peter Seddon" <[email protected]>

> >> What advantages over fitting a chain do they
> >> offer ?
> >
> > In theory, compared with a new chain, correctly adjusted, nothing.
> >
>
> Timing belts a la 300 TDi tend to snap not stretch.
>
> Peter

Agreed, although this comment was about chains, not belts. The
weaknesses of the belts are well-known, but the question was on the
advantages of gears over a chain.

Rich

Hi Nick,
can't agree on the fact that modern timing belts don't
stretch.
I have seen on the 300Tdi where the belt had stretched to the point
that the amount of slack between the pump and cam shaft had reached
the point that you could push the belt all the way up to the inside of
the timing case. In fact in one case we could have gone further but
the case stopped the "experiment". We checked the tensioners etc and
they were still properly tightened, so we could only put the looseness
down to belt stretch.

As to a before and after study, if you look at the bottom of the page
at the address below you will find such a study. This was done at the
Chisholm Institute which is a "technical college" that trains
apprentice mechancs, amongst a number of science based disciplines,,
and is the closest 4wd dyno to me.

http://www.yican.com.au/tbd.html


The before had a new timing belt fitted as per LR specs etc by local
dealer. After nearly 4000km the before test was done. After this,
nothing was changed, except the Zeus gears were fitted, and then after
they had run for a while taken back for the after study. If anything
there was a potential for problems because the air filter was the same
used. Fuel is always purchased locally from the same place so this is
unlikely to be a factor.


As a double check, the experiment was run on a Defender with only
20000kms on it and the results were the same. This vehicle is owned by
an ex Navy man, who is very particular about his servicing-runs a
engine running hour meter so can be described as fairly precise on how
he does things.

Hope this helps answer or address some of your queries.


Cheers


Phillip Simpson



On 1 Nov 2004 04:36:56 -0800, [email protected] (Nick C)
wrote:

>> Hi Peter,
>> have to agree that they can snap, but also disagree about them
>> stretching. In fact if you fit a belt part of the installation process
>> is to tighten them tightly, turn the engine around a couple of times,
>> and then retighten them. Even with this process they stretch in a very
>> short time.
>
>the amount of stretch is almost imperceptable on modern timing belts.
>When i compared my old belt against the new belt for wear when i
>changed it last, i could not tell any difference due to stretching.
>Can`t say i was looking too hard though. Looking at the length of the
>belt fitted to a 300tdi and assuming a 2 degree error would be
>noticeable in the timing, the belt would need to stretch 5mm in
>length!!! Mine certainly hadn`t after being used and definitely abused
>for 60,000 miles!
>>
>>
>> Speaking to owners I had one customer who noticed that over a period
>> of some 9 months his vehicle was slowing loosing power. (he and a
>> fishing mate, used to both drive up a long steepish hill in their
>> vehicles. Initially the 300Tdi always beat the Pajero(Shogun?) but
>> this changed to a draw, then the pajero would always win the race up
>> the hill.)
>
>You`ll probably find that was more to do with fuel and air filters and
>lack/need of a service than the timing belt. Defenders are very prone
>to clogging up air filters with dust and it makes a huge difference to
>the performance. I didn`t notice ANY difference in power before and
>after the belt was done. None at all. And i use low rev power ALOT as
>its constantly used offroad and for dragging caravans around. However
>about 3000 miles after a service it gets very sluggish and i usually
>end up doing a mini service to replace the air filter. normal power is
>then returned.
>>
>
>> Even with a new belt I've never seen a 300Tdi pull properly down to
>> 1100rpm like I can do anytime I need to (mud,snow,sand driving etc).I
>> also like the extra economy you get from the 300Tdi with the gears,
>> especially since the price of fuel is increasing.
>>
>>
>You`ve never driven mine then! My defender 300tdi is completely
>standard (engine wise) and pulls like a trojan horse from tickover. A
>properly set up tdi is a brilliant engine. More likely factors in
>performance would be injectors, air and fuel filter, correctly set up
>injection pump, lift pump working properly (amazing how many tdis
>suffer poor performance from weak lift pumps not supplying enough
>motion lotion!) and carbon build up in the head.
>
>I may be swayed if you were able to give independant comparisons of
>rolling road / dyno tests of brand new engines before and after the
>conversion.
>
>
>> Cheers
>>
>Nick

Phillip Simpson wrote:
> Hi Nick,
> can't agree on the fact that modern timing belts don't
> stretch.
> I have seen on the 300Tdi where the belt had stretched to the point
> that the amount of slack between the pump and cam shaft had reached
> the point that you could push the belt all the way up to the inside of
> the timing case. In fact in one case we could have gone further but
> the case stopped the "experiment". We checked the tensioners etc and
> they were still properly tightened, so we could only put the looseness
> down to belt stretch.

Was it definitely fitted as per workshop manual ?

Steve

Hi Steve,
it was fitted by Land Rover in Solihul, so we must assume that
it was.
This was interesting as the 2 owners who used to race to their
favourite fishing spot, had both purchased new vehicles. One was a
disco and the other the pajero. As I said the disco won the hill race
for the first 12 months and then slowly the pajero was catching up and
then eventually overtook the disco. Had both drivers present when we
opened the disco up, and the various comments from both drivers was
predictable and very funny. It should be noted that both these guys
were retired, and what could be described as "mature gentlemen". After
fitting the gears the pajero driver was to become very familar with
the disappearing rear end of the disco, and as far as I know that this
is still the case after 2 years.

Cheers

Phillip

On Mon, 01 Nov 2004 23:34:09 +0000, Steve Taylor
<[email protected]> wrote:

>Phillip Simpson wrote:
>> Hi Nick,
>> can't agree on the fact that modern timing belts don't
>> stretch.
>> I have seen on the 300Tdi where the belt had stretched to the point
>> that the amount of slack between the pump and cam shaft had reached
>> the point that you could push the belt all the way up to the inside of
>> the timing case. In fact in one case we could have gone further but
>> the case stopped the "experiment". We checked the tensioners etc and
>> they were still properly tightened, so we could only put the looseness
>> down to belt stretch.
>
>Was it definitely fitted as per workshop manual ?
>
>Steve